Loaders are frequently left unguarded at a job site and, because of their size, it is a relatively simple matter to steal a loader by driving it onto a small trailer and hauling it away. Theft or unauthorized use is further simplified because an operator may frequently forget to remove the ignition key when he leaves the loader. Therefore, it is desirable to provide some means for deterring theft or unauthorized use of a loader even though the ignition key is available for starting the loader.